Coupling for conduit outlet-boxes.



No. 675,l27. Patented May 28, l90l.

.1. A. COLE."

COUPLING FOB OONDUIT OUTLET. BOXES.

(Application filed Sept. '15, 1900.

(No Model.)

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UNITED I STATES PATENT OFFICE.

JOHN APPLETON GOLF, OF BOSTON, MASSACHUSETTS.

CDUPLING FOR CONDUIT OUTLET-BOXES.

SPECIFICATION forming part of Letters Patent No. 675,127, dated May 28,1901.

Application filed September 15, 1900. Serial No. 30,162, (No model.)

To aZZ whom it may concern:

Be it known that 1, JOHN APPLETON COLE, a citizen of the United States,and a resident of Boston, county of Suffolk, State of Massachusetts,have invented an Improvement in Couplings for Conduit Outlet-Boxes, ofwhich the following description, in connection with the accompanyingdrawings, is a specification, like figures on the drawings representinglike parts.

This invention relates to couplings for conduit outlet-boxes such as areused in systems of house-wiring.

It is the common practice at present in wiring a house for electriclamps or other purposes to provide the walls of the house with suitableconduits, generally of gas-pipe, which may be lined with some suitableinsulating material, and to use such conduits for carrying the wiresfrom one place to another, the conduits terminating at the places wherevthey are brought to the surface of the walls in outlet-boxes, saidoutlet-boxes being of a variety of shapes and of various constructions,according to the particular use to which theyareapplied. In theconstruction of such outlet-boxes it is essential that they be madewater-tight and also that the conduithave a perfect electricalconnection with the box, so that the entire system may be grounded.

It is the object of my invention to provide a coupling for connectingthe conduit to an outlet box which will be watertight and which willinsure an electrical connection between the conduit and outlet-box.

The outlet-box which I preferably use will have one or more openings inits sides, according to the requirements of the place where it is to beused, and I may, if desired, make my box of such a material that thesaid openings may be punched in the sides of the box when the box is putin place, and in these openings suitable couplings are secured, thecouplings having connected thereto the conduits which support the wires.

I may make my couplings of some suitable non-corrosive material, ifdesired.

The couplings are each made with a reduced portion at one end, saidreduced portion terminating in a shoulder or iiangeand being adapted tobe inserted into the opening in the sideof the box, the flange orshoulder abutting against the box, and suitable means are provided forholding said shoulder tightly against the box, said means being soconstructed as to make a perfect electrical connection between thecoupling and the box.'

Figure 1 is a View of one form of box with my couplings attachedthereto, the cover and one side of the box being partially broken away.Fig. 2 is a side elevation of the parts shown in Fig. 1, and Fig. 3 is adetail of the coupling.

The outlet-box is designated by-3, and this will be made of variousshapes, according to the requirements of the particular place where itis to be used, the outlet-box illustrated in the drawings being anoctagonal box.

I preferably make my outlet-box of some suitable non corrosivematerial-such, for

' instance, as an alloy of aluminiumthe said outlet-box being made froma single piece or blank by pressing or stamping it into shape by meansof suitable dies, thus making a seamless outlet-box and one which isabsolutely water-tight.

In construction of the box the sides of the box are integral-that is,they are made solid without any openings thereinthe opening for thecouplings being punched in the side of the box by any suitable mechanismwhen the box is about to be placed in position, the material used inmaking the box being such as can be easily punched.

By making my box of an alloy of aluminium, which is non-corrosive, thelife of the box is lengthened, since there is no dangerof its rustingaway, nor is there any danger of rust accumulating between the box andthe coupling, as in the case of iron or other material.

The cover 4 will of course be of any suitable construction, suchconstruction varying according to the particular use to which the box isapplied, and in the drawings I have merely represented a plain cover toshow the way in which the cover is attached to the box, it beingunderstood, of course, that my invention is not limited to theparticular form of cover, but only to the way in which the cover isattached to the box.

In order to make a water-tight connection between the cover and theoutlet-box, I provide my outlet-box at its top or open side with theoutwardly-projecting flange 5, which flange forms a seat extendingentirely around the box, on which the cover is adapted to rest, andpreferably I provide a gasket 6, of any suitable material,which isplacedbetween the cover and the flange 5, the cover being fastened to theflange by any suitable means, such as screws 7, passing through thecover and screwing into apertures 8 in said flange. By means of thisconstruction the cover makes a perfectly water-tight joint with theoutletbox, which is'an essential feature in devices of this nature.

The coupling member is designated by 10, and this is also preferablymade of'a suitable non-corrosive material--such, for instance,as thatspecified above-and it presents at one end the reduced portion 11, whichterminates in the flange or shoulder 12, the said reduced portion beingadapted to be inserted through the opening 13 in the side of the box andsaid shoulder or flange 12 abutting against the outlet-box, asillustrated in Fig. 1. The shoulder or flange 12 is made square, so thatit fits accurately against the side of the outlet-box, and in order toclamp it firmly in such position to thereby make a water-tight jointbetween the coupling and the box I preferably provide the reducedportion 11 with exterior screw-threads, upon which a nut Misadapted toscrew, thereby clamping the outlet-box side firmly between the nut andshoulder 12. The

end of the coupling member opposite the redu'cedportion 11 is connectedto the conduit 15 by making the coupling member with the elongatedcylindrical portion 17, which is provided with interior screw-threads16, which are adapted to engage exterior screw-threads on the end'of theconduit 15, the long cylindrical portion 17 of the coupling memberproviding means for adjusting the relative positions of the conduit andoutlet-box without detaching one from the other. As seen in Fig. 8, theinterior screw-threaded portion of the coupling 10 terminates in theshoulder 25, said shoulder being preferably of a depth equal to thethickness of the material in the conduit, so that when the conduit isscrewed into the coupling the end thereof will abut against the shoulder25 and the interior bore thereof will present a smooth and continuoussurface with the bore of the reduced portion llpwhereby the system willpresent a continuous and smooth surface for the wires from one outlet tothe other.

In perfect house-wiring systems'it is essential that the conduits andboxes be grounded, audit is therefore necessary to provide means forinsuring perfect electrical con tact between the conduits and boxes. Ihave provided means for thus electrically connecting the conduits andboxes by providing the inside of the nut 14. with suitable .points 20,which as the nut is screwed up to clamp the outlet-box between it andthe flange 12 cut into the side of the outlet-box, as illustrated inFig. 1, there by cutting through any rust or paint or other materialwhich may be on the inside of the box and forming a perfect electricalconnection between the outlet-box and the nut. The not, of course, byits screw-threaded engagement with the coupling 10, has an electricalconnection therewith,and the couplingis electrically connected with theconduit.

The interior bore of the reduced portion 11 of the coupling member isprovided with a coating of any suitable insulated material 21, so thatthe wires contained in the conduit and merging from the coupling will bethoroughly insulated from the outlet-box.

As is usual with this class of devices, the bore of the coupling memberwhere it merges into the box is made round, as shown in Fig. 3,-so thatthe insulating material on the wires will not be injured by being drawnovera sharp edge.

It will be obvious that changes may be made i in my device, asillustrated in thedrawings,

without departing from the spirit of my invention as expressed in theappended claims.

Having described my invention, what I claim as new, and desire to securebyLetters Patent, is'' 1 1. A coupling for conduit outlet-boxes,comprising a coupling member having at one end aninteriorly-screw-threaded portion into which the end of a conduit isadapted to be screwed, and at the opposite end areduced portionterminating in a square shoulder or flange, said reduced portion beingadapted to be inserted in an openingin the side of an outlet-box, andthe shoulder adapted to abut against the outside of the box, and meanson the reduced portion adapted to engage the inside of the box and toclamp the side of the outlet-box between the same and the shoulder, tothereby form a water-tight joint.

2. A coupling for conduit outlet-boxes, 4

whereby a water-tight connection is made,

the opposite-end of the coupling member being interiorly screw-threadedto receive the end of a conduit, said coupling having an interiorshoulder against which the end of the conduit is adapted to abut,whereby a continuous smooth surface is presented to the wires fromoutlet to outlet.

3. A coupling for conduit outlet-boxes, comprising a coupling memberhaving at one end a reduced screw-threaded portion terminating in asquare'shoulder or flange, said "reduced portion being adapted to beinserted in the side of an outlet-box, a nut on the said reduced portionadapted to clamp the side of the box between the same and the shoulder,and means for insuring an electrical connection between the nut and thebox.

4. A coupling for conduit outletboxes, comprising a coupling member madeof noncorrosive material, having at one end a reduced screw-threadedportion terminating in a square shoulder or flange, said reduced portionbeing adapted to be inserted in an opening in the side of an outlet-box,a nut on the said reduced portion adapted to clamp the side of the boxbetween the same and the shoulder, to therebyform a water-tight joint,the said nut having a series of points which cut intothe outlet-box sideas the nut is screwed up to thereby insure an electrical connectionbetween the coupling and the outletbox;

JOHN APPLETON COLE.

Witnesses:

JOHN C. EDWARDS, Louis 0. SMITH.

